| 摘要 |
In a subscriber set for push-button dialling in which a first electronic switch (15) is connected upstream of the speech circuit (3) and a second electronic switch (16) is connected upstream of the dialling circuit (4) and in which, by means of a bridge rectifier (2), a switchover from dialling mode to speech mode which is independent of the respective polarity of the subscriber line (1) is enabled by a dialling circuit (4), the speech circuit is disposed upstream of the bridge rectifier rather than downstream as it had been previously to prevent a reduction in the power available for the speech mode and an inverting switching stage (7) is inserted between the dialling circuit (4) and the first electronic switch (15) which supplies the first electronic switch with each control voltage with both polarities. <IMAGE> |
